Table 2.

IGRA performance characteristics with respect to TB prevalence.

Performance characteristics	TB prevalence	IGRA
Sensitivity	–	69% (95% CI, 42–87%)
Specificity	–	90% (95% CI, 84–94%)
PPV	2%	12%
NPV		99%
+LR		0.14
−LR		0.007
PPV	10%	43%
NPV		96%
+LR		0.76
−LR		0.38
PPV	15%	55%
NPV		94%
+LR		1.2
−LR		0.06

PPV, positive predictive value; NPV, negative predictive value; +LR, positive likelihood ratio; −LR, negative likelihood ratio.